1Combine all ingredients in a medium nonreactive mixing bowl and toss to thoroughly coat strawberries. Let macerate at room temperature at least 20 minutes before using.
2Strain macerated berries and reserve syrup separately.
For the cake:
1Heat oven to 350°F and arrange rack in upper third. Butter and flour two (8-inch) cake pans. Sift flour, baking powder, and salt together into a mixing bowl; set aside.
2In the bowl of a stand mixer fitted with the whip attachment, combine vegetable oil, water, lemon zest, vanilla extract, egg yolks, and 1 1/4 cups of the sugar. Whip on medium speed, until mixture is airy and light in color, about 5 to 7 minutes. Turn off the mixer and scrape down the sides of the bowl; add dry ingredients and whip until smooth, about 1 minute more.
3In a clean bowl, whip egg whites to medium peaks. Add remaining 1/4 cup sugar and continue whipping until stiff peaks form, about 1 minute more. Using a rubber spatula, fold 1/4 of the egg whites into the cake batter until evenly incorporated; gently fold in remaining egg whites until just combined.
4Divide batter between prepared cake pans. Bake until surface of cakes springs back when pressed and a toothpick or cake tester inserted into the center comes out clean, about 30 to 35 minutes. Remove cakes from the oven, and let cool 15 minutes. Run a knife around the perimeter of each, and turn them out onto wire racks to cool completely. Meanwhile, make the filling and the frosting.
For the filling:
1Combine mascarpone cheese and heavy cream in the bowl of a stand mixer fitted with the whisk attachment, and whip until stiff peaks form, about 2 minutes. Cover and refrigerate until ready to use.
For the frosting:
1Place the cleaned bowl of the stand mixer and the whip attachment in the freezer for 10 minutes. Combine vanilla extract, sugar, and heavy cream in the chilled bowl and whip at medium speed until medium peaks form, about 2 minutes.
2Cover and refrigerate until well chilled, at least one hour. (The frosting can be prepared up to 12 hours ahead.)
1Using a long serrated knife, trim the tops of the cakes as necessary so they are level. Place cake rounds on a clean, dry surface and, using a pastry brush, brush 1/2 of the reserved strawberry syrup on the cut side of the first cake round; repeat on the cut side of the second cake round.
2Evenly spread 1/4 of the mascarpone filling over the cut side of the bottom cake layer. Arrange strawberries standing upright, stem end down, over the mascarpone layer and trim as necessary to create an even layer. Cover berries with the remaining filling, being sure to fill in any empty space.
3Place second cake layer over mascarpone and strawberries, cut side down, pressing gently to secure it. Using an offset spatula or a long, thin spatula, spread 3/4 cup of the frosting in a thin layer over the top and sides of the cake. Return remaining frosting and cake to the refrigerator until frosting on cake is set, about 15 minutes.
4Spread the remaining frosting all over the top and sides of the cake. Let sit in the refrigerator at least 15 minutes before serving.